Morus Alba is the White Mulberry, although the fruits are what 'White Mulberry' refers to the stems and leaves are also commonly used as a tea and, more recently, in supplements as ethanolic/ethyl acetate extractions (supplements, or a wine extraction) appear to concentrate the bioactives. The term Morus can be seen as synonymus with the common word 'Mulberry' where the species of Alba literally means White (derived from the Latin term Albus). Other Morus herbs differ in their coloration, such as Morus Nigra (Black Mulberry) and are not the subject of this article.
White Mulberry has had all parts of it used in Traditional Chinese Medicine for a variety of purposes, but currently most evidence on Morus Alba is in regards to its anti-diabetic properties. Surprisingly, there is a large body of repeated rodent evidence to suggest it effective in reducing blood sugar regardless of previous state (toxin-induced diabetic, diet-induced diabetic, genetically diabetic or normal rodents) but with no current human evidence.
It merely appears to inhibit absorption of carbohydrates from the intestines, with most potency on inhibiting sugar absorption (fairly weak in inhibiting starch absorption, but is synergistic with Hibiscus Sabdariffa on this which would make a nice combination). For the most part, this is tied back into the iminosugar compound known as 1-deoxynojirimycin which is a glucose molecule with a nitrogen attached it it; it inhibits enzymes that have affinity for sugars via competitive inhibition where the enzyme is attracted to the glucose structure but cannot act effectively due to the nitrogen group (which does not exist on sugars normally and hinders the enzyme's functions)
There appear to be promising cognitive effects associated with Morus Alba as well, with some evidence suggesting it can increase memory formation and cognition to a level similar to Piracetam; interesting, there are some pyrrole alkaloids in Morus Alba (a structural class of molecules that Piracetam belongs to) but these have not yet been connected to the observed cognitive benefits.
Morus Alba may also have respectible benefits to cardiovascular health (with improvements in circulating lipids and cholesterol, with fairly potent reductions in atherosclerotic plaque buildup possibly related to potent in vitro anti-inflammatory properties) but similar to the other claims these have not yet been tested in humans.
Currently, the evidence suggests that Morus Alba is a highly promising functional food and tea product that may have benefit as a supplement especially in regards to cognition and glucose control but currently does not have sufficient evidence to suggest how potent these benefits are in humans and whether or not Morus Alba is a 'go-to' supplement.